The present invention relates to a method for manufacturing an armature, a method for manufacturing a motor, and an armature.
In general, the armature in an electrical machine with rotating parts, such as a motor, has a core that has radially arranged teeth. A coil is wound about each tooth. In the armature having such a core, various configurations have been proposed directed to space factors. For example, a core has been proposed, which is constituted by combining a plurality of split core members having an annular portion and at least one tooth radially extending from the annular portion (see Japanese Laid-Open Patent Publication No. 9-46941, Japanese Laid-Open Utility Model Publication No. 63-187545, Japanese Laid-Open Patent Publication No. 9-322441, Japanese Laid-Open Patent Publication No. 2002-291183, and Japanese Laid-Open Patent Publication No. 2002-369421). In such cores, after winding a coil on the teeth of each split core member, those split core members can be mutually assembled. Hence, without being hindered by adjacent teeth, a coil can be wound about each tooth, thereby forming the armature having a high space factor.
In the meantime, the manufacturing process for the motor, after having wound a coil on each tooth, includes a process of pressing the armature and a commutator into a rotary shaft, and connecting the end portion of each coil to the commutator. However, in general, the coil used for the motor comprises a relatively soft wire such as a thin copper wire, and is unable to maintain its shape by itself. Hence, after having wound the coil on each tooth, if its end portion is let loose once, it becomes difficult to grip the end portion again when attempting to connect it to the commutator in a process in which an assembly is automated, thereby bringing about a deterioration of productivity. Hence, it is necessary to hold the end portion of the coil during the time from the coil is wound about each tooth till the end portion of each coil is connected to the commutator. However, if the mechanism to hold the end portion of the coil is provided in the armature, the size of the motor is increased.